Author Topic: Why would I want to 'Enable Seams' when baking curvature maps?  (Read 1039 times)

I noticed this option in the texture baking options under curvature. It is on by default. And basically what it seems to do, is put a hard black line on the curvature map over all of your UV seams.

And really, this just seems like such an odd feature, and I can't fathom what use having those lines on a curvature map would ever serve.

What is the reasoning behind this feature? Under what circumstances would I want to use it?

I've been wondering the same thing since I started using Painter.

There are certain situations where using your UV seam as a type of border/outline can be useful. I've used the UV-Border generator to create perfect/straight outline edges before. Unlike the curvature map, it is not subject to defects and artifacts - the outline edges are always perfect. I've used it to create things like welded cavities. I would assume that baking option exists for similar reasons, but would still like to know the official intended usage of it.
Last Edit: February 24, 2019, 11:44:56 pm

It's fairly baffling. Take this bake for example:


I don't have Enable Seams checked. And that diagonal isn't even on a seam. I have no idea where that data is coming from.

EDIT: Enable Seams was on actually, for some reason. I was baking four texture sets at once, and for some reason just this one used Enable Seams, while the others didn't. I still don't get that diagonal, in any case.
Last Edit: April 03, 2019, 08:55:04 pm

That option's name is indeed confusing. As far as I remember the intent is not to "make seams visible in the curvature" at all. I suppose it should be named "try to make seams due to the normal map less visible" (which means that most of the time you want it on, but since it can fail and make things worse, sometimes you may want it off). Now I would have to look at the code to find out which way it is supposed to be when the option is checked, as it does not seem to be doing a good job at it either way currently.

@Rekov : I suspect that problem with the diagonal line in your picture is not related to the "Enable Seams" feature at all. I would suspect more a numerical precision issue, maybe due to the very small bevel in your low poly
Last Edit: April 04, 2019, 07:01:30 pm

Leaving aside the oddity of that diagonal edge, here is what enable seams does as far as I can tell: It paints a 1px thick line in black (i.e. fully concave) along all of the seams. I can sort of understand wanting a mask that targets seams so that you can try to cover them up, but this doesn't do that.



Enable Seams especially doesn't seem to work when seams are along convex corners, because it paints a thin line of concavity right in their middle. It's almost as if Enable Seams was only designed to work along concave edges.


As far as I remember the intent is not to "make seams visible in the curvature" at all. I suppose it should be named "try to make seams due to the normal map less visible" (which means that most of the time you want it on, but since it can fail and make things worse, sometimes you may want it off).
Yeah, if anything it almost seems to be doing exactly the opposite of what I would think it ought to be doing. I can't tell if it's making that concave seam more or less visible, but it's certainly not helping the convex one. I almost want to say it should be painting a white line instead of a black one on those convex areas, as that would be fixing the seam more.



Last Edit: April 04, 2019, 07:16:36 pm